Radioreceiver



May 31, 1932. GRlGSBY 1,860,348

RADIORECEIVER Filed May 28, 1928 3 Sheets-Sheet 1 Z9 1% May 31, 1932. B. J. GRIGSBY 1,860,343

I RADIORECEIVER Filed May 28, 1928 v 5 Sheets-Sheet 3 Patented May 31, 1932 UNITED STATES PATENT OFFICE IBERTRAM J; GRIG'SBY, OF PARK RIDGE, ILLINOIS, ASSIGNOR r GRIGSBY-GRUNOW COMPANY, or CHICAGO, ILLINOIS, A oonronA'rIon or ILLINOIS *RAnIonEonIvEa Application filed May 28,

My invention relatesin general to radio receivers. It rel-ates more. in particular to an improved type of loud speaking reproducer, and particularly the combination of such a speaker in certain novel forms with the cabinet in which the radio receiver is housed.

The radio reproducer which I employ is of the type disclosed in Patent Number 1,644,387, issued to G. Kyle on October 4, 1927 and comprises briefly a stationary perforated metal member, and a flexible metal member, with a dielectric diaphragm between the two metal members. In its usual form the dieelectric diaphragm is in the'form of a flexible rubber or rubberized sheet, and the flexible metal member is in theform of gold leaf or a similar material pasted or otherwise secured to the rubber diphragm. By connecting one terminal of the speaker current to the stationaryplate and the other terminal to the movable metal diaphragm, an electrostatic action takes place causing a sound vibration of the flexible metal plate and the rubber diaphragm to which it is secured.

In combination with the radio receiver I mount the speaker into the cabinet to form a part thereof, thus saving space and securing other advantages which will appear from the following description.

In the accompanying drawings I illustrate several applications ofmy invention showing the use of the speaker through different specific combinations, and in such drawings Fig. l is a fragmentary plan view of a radio receiver with the cover removed and constructed in accordance with my invention;

Fig. 2 is a fragmentary front elevational view of the same device as shown in Fig. 1;

Fig. 3 is a front elevational view of a style of cabinet which may be employed in carrying out my invention;

Fig. 4 is a sectional View such as might be taken along the line lof Fig. 3 and showing the speaker built into the lower section of the cabinet;

Fig. 5'is an enlarged view of a small portion o1 Fig. 4;

Fig. 6 is a sectional view such as might be 1928. Serial No. 280,994.

taken along line 6-6 of Fig. 3 looking in direction of the arrows, and showing the invention as applied to the apparatus housing portion of the cabinets;

Fig. 7 shows another manner of applying a speaker to the lower portion of a radio cabinet, that is to say in a portion of a cabinet in which the apparatus is not housed, and

Fig. 8 is a fragmentary view showing the use of the speaker itself as a front panel for supporting the control apparatus.

In order to make the details of the invention clearer to those skilled in the art I shall first describe the details of the speaker unit in order that its features, and the difficulties to be overcome in employing it in the combinations shown may be understood. Referring first to Figures 2 and 5 the speaker comprises a relatively heavy or stifi' metal plate 10 provided with perforations 11 and slightly waved; a section of dielectric material 12, and a thin sheet of conducting material 13. For the dielectric material 12 I employ a thin piece of silk rubberized so as to form a very thin coating of rubber on one side thereof. The flexible conducting portion 13 is preferably gold leaf adhesively secured to the rubberized silk. The perforated plate 10 is slightly curved as shown so that the dielectric diaphragm will lie closely against it, and the diaphragm is secured to the edges of the perforated metal plate in any suitable manner, as by a marginal clamping frame A.

Referring now to Figures 1 and 2 wherein the speaking unit is employed as the front panel in the apparatus housing portion of the cabinet I show a cabinet provided with corner posts 14 to which are connected the usual wooden panels 16. A radio receiver 17 is shown schematically and is supported in any suitable manner in the cabinet, it being preferably mounted on a separate chassis or self supported as is now usual in the art. I show it equipped with three dials which may be considered as selectivity control 18, selector switch 19 and volume control 21, these dials connecting to suitable apparatus not shown herein. The selector switch 19 turns an indicator 22 which is efiective to show the wave length to which the receiver is tuned,

and as is now usual in the art, is connected to and turns with a condenser or condensers by means of which the tuning is effected.

In the embodiment of Figures 1 and 2 the speaker here indicated by reference character 23 for purpose of identification is mounted at the front of the cabinet and has a protective partition 24 mounted in front of the same. The protective part 24 is in the form of a grille here shown as a wooden panel with a series of vertical slots, but in actual practise any ornate design can of course be used. The speaker 23 and its protective panel in this embodiment do not support the apparatus but are simply apertured to permit the control shafts to extend therethrough so that the usual control knobs may be mounted on the outside; In securing the speaking unit 23 in place I employ any suitable molding secured to the post 14 by wood screws 27. The protective partition 24 fits in against a shoulder provided on the post 14 so as to be held away from the speaker and it is held in placeby molding 28 secured to the post 14 by wood screws 29.

Referring nowto Fig. 4 I show the reproducer mounted in the'cabinet so as to form a part thereof and assist in supporting the cabinet itself. Here the speaking unit 123 lies in against shoulders provided in the post 114 and mounting strips 131 are secured to the post by wood screws 132 so as to mount the speaker semi-permanently in place. At the same time this construction permits the removal of any one of the speaking units for the purpose of repair or the like. Four units are shown, one in each wall of the cabinet so that there is ample area toobtain. all the volume that could be desired under all circumstances. Each of the units is protected by a grating 124 removably held in position by any suitable means.

Fig. 6 shows the speaking unit mounted in three sides of the portion of the cabinet housing the receiving apparatus. In this embodiment the post 214 is mounted ermanently with the protecting panels or grille work 224, the usual solid panel such as was indicated by the reference character 16 in Fig. 1 being replaced by grille work so that the grilles serve as an actual part of the cabinet. The speakers'223 are mounted inside the cabinet and are provided with a wooden or similar frame 233 which is removably secured to the corner post on the inside of the cabinet. This cabinet houses the usual apparatus 217 operated by dials 218, 219 and 221 which project through a solid front panel 234 such as that used in the ordinary or conventional type of set.

With the arrangement shown in Fig.6 a considerable area of speaker is provided with a standard piece of apparatus all mounted compactly in a relatively small cabinet thus conducing to the conservation of space and the producing of a qualit receiver at a relatively low price due to t e savings in material, etc.

In the embodiment of Fig. 7 the usual corner posts 314 and wooden panels 316 are employed, with the front panel shown as a grating 324. The speakers 323 are provided with a marginal frame which is secured to the post on the inside of the cabinet, with the speaker facing toward the inside of the cabinet and with three units, one at the back and one at each end, all adapted to be heard through the grating 324. This construction is of importance where a relatively large cabinet of de luxe design is to be used. The entire lower portion of the cabinet can be equipped with the front grating, with the speaker operating through the grating, and the apparatus portion of the receiver housed in an upper portion thereof. Or the speaker may be in the upper portion of the cabinet with the apparatus below. With the speaker above the top of the cabinet may be provided with grille work if desired, but I prefer to have the top or lid of the cabinet of solid construction.

In the embodiment of Fi 8 which I show only on a small scale a suitable piece of apparatus 41 which may be a condenser, rheostat or the likehas its shaft 42 extendin through the speaker 23. A dielectric was er 43 is mounted on one side of the speaker and a dielectric washer 44 on the outside thereof, a nut 46 being employed to mount the apparatus in place, this nut being threaded on a sleeve 47 which also projects through the speaker and in which the shaft 42 is journaled. In this way the apparatus is fully insulated from the speaker and is also firmly mounted thereon.

In the attached claims I employ the term panel to refer to any one of the thin sections of material between the cabinet uprights, such a panel being either a front, side or back panel, and while I do not disclose it in the drawings it might for certain purposes be considered to mean a top or bottom panel as well. I employ the term grille or grating to refer to the member which serves as a protection solely for the reproducer, while the term apparatus panel is employed to refer to the thin walled member on which the control apparatus is mounted. By the term electrostatic reproducer or speaker I mean any panellike unit operating according to the principle disclosed in the prior patent referred to and consisting essentially in a pair of conducting plates separated by dielectric material so that one of said plates is adapted to vibrate in response to the voice current.

While I have described several modifications and many detailed features of my invention I do not intend to restrict myself except as define'd in the appended claims.

What I claim as new and desire to protect by United States Letters Patent is:

1. In a radio receiver-the combination with a cabinet serving to house the receiving apparatus of an electrostatic reproducing unit having a substantially plane surface mounted in the cabinet and serving as one of the panels thereof.

2. In a radio receiver the combination with a radio apparatus housing cabinet having a plurality of uprights connected with panels of an electrostatic reproducer having a substantially rigid surface serving as one of said panels and forming part of the structure of said cabinet.

3. In a radio receiver an electrostatic reproducer formed as a self contained unit and forming the Wall of a cabinet, a cabinet adapted to house radio receiving apparatus, and means for removably supporting the self contained unit in said cabinet.

4. In a radio receiver an electrostatic reproducer comprising a stationary metal pl ate, a flexible dielectric diaphragm and a flexible metal member secured to said diaphragm, a marginal frame for clamping said diaphragm to said metal plate, a cabinet housing radio receiving apparatus, and having a pluralityof uprights connected with panels, and means for securing the marginal frame to the uprights to incorporate the reproducer into the cabinet in lieu of one of said panels, and a grille secured between uprights outside of said reproducer, said marginal frame being formed wide enough to prevent the grllle from contorting with said reproducer.

5. In a radio receiver an apparatus housing cabinet, having a plurality of uprights and a grilled panel connected between the uprights to form an integral portion of the cabinet, and an electrostatic reproducer having a slightly concave surface provided with a marginal frame and constituting a selfcontained unit removably secured to the cabinet on the inside of said grilled panel and adapted to be heard therethrough.

6. In a. radio receiver the combination with an apparatus housing cabinet having a plurality of uprights and panels between the uprights, of an electrostatic reproducer having a substantially plane surface serving as one of said panels and forming part of the structure of said cabinet, and means secured to the cabinet on the outside of the reproducer for protecting said reproducer and passing sound out of the cabinet.

7.7 In a radio receiver the combination with an apparatus housing cabinet having a plurality of uprights and panels between the uprights, of an electrostatic reproducer having a substantially plane surface serving as one of said panels and forming part of the structure of said cabinet, and a grille secured to the cabinet and enclosing said reproducer.

8. In a radio receiver the combination with an apparatus housing cabinet havingra plurality of uprights and panels between the uprights of an electrostatic reproducer having a substantially plane surface formed concavo-convex and sccured'into' the cabinet as a part thereof and in place of one of the standard panels with the convex side facing outwardly, a grille secured to the cabinet of said reproducer and means for spacing the edges of the grille away from the edges of the reproducer a sufficient distance to allow for the curve of said reproducer.

9. In a radio receiver the combination with an apparatus housing radio cabinet having a plurality of uprights and panels between the uprights of an electrostatic reproducer having a substantially plane surface secured to the uprights for producing sound Within the cabinet, and a grille panel for permitting free movement of the sound wavesout of the cabinet.

10. In a radio receiver the combination with an apparatus housing cabinet of an electrostatic reproducer having a substantialiy plane surface mounted as the front panel of said cabinet and apertured to permit apparatus control means to pass therethrough for control of the receiver through said reproducer. i

11. The combination in a radio receiver of a cabinet housing radio apparatus and an electrostatic reproducer having a substantially plane surface mounted as the front panel of said cabinet, and a protecting grille for said reproducer, both said reproducer and grille being apertured to permit passage of apparatus control shafts therethrough.

12. In a radio receiver an electrostatic reproducing unit serving as the apparatus panel, apparatus mounted behind said panel and means for insulatingly securing said apparatus to said reproducing unit having asubstantially plane surface.

13. In a radio receiver an electrostatic reproducer comprising a stationary metal plate, a flexible dielectric diaphragm and a flexible metal member secured to said diaphragm, a marginal frame for clamping said diaphragm to said metal plate, a cabinet housing radio receiving apparatus, and having a plurality of uprights connected with panels, and means for securing the marginal frame to the uprights to incorporate the reproducer into the cabinet in lieu of one of said panels.

14. In a radio receiver the combination of a cabinet having a plurality of sides, an electrostatic reproducer unit on each of a plurality of sides thereof, corner supports for securing said units along their edges to maintain them in position and leaving their surfaces free to vibrate, and means for actuating said units simultaneously to reproduce sound.

15. In a radio receiver the combination of a cabinet havin a plurality of sides, an electrostatic repro ucer unit on each of a plurality of sides thereof, means for supportingsaid units along their edges leaving their 5 surfaces free to vibrate, a grille for protecting said units, and a receiver for actuating said units to reproduce sound.

16. A combined electrostatic loud speaker and radio receiver in which a perforated metal plate which forms one conductive member of the condenser constituted by the loud speaker forms also a housing for the radio receiver.

, 17. In combination a radio receiver, a per- 1 forated metallic housing for said receiver, an

elastic insulator upon said housing, a conductive coating upon said insulator and means for supplying output potentials from said receiver between said housing and said conductive coating.

18. In combination a radio receiver, a perforated'metallic housing for said receiver, an elastic insulator upon said housing, a conductive coating upon said insulator, means for supplying output potentials from said receiver'between said housing and said conductive coating, and a protective casing about said coating.

In witness whereof, I hereunto subscribe my name this 22nd day of May, 1928.

'BERTRAM J. GRIGSBY. 

